Hi Matt:
To change the differential fluid, I recommend getting an inexpensive lube pump at your local auto parts store and then pumping the old stuff out.
You can also use the same pump to out the new gear oil back in. Mobil 1 and Royal Purple gear oil are both synthetic and work well.
For your T case, you will need a 3/8th hex allen wrench that will removed the two allen plugs on the rear of your T case.
After draining, reinstall the bottom plug and then fill till it begins to run back out of the upper hole with Valvoline ATF+4.
Your rear axle will take about 70 ounces, and the T case will be about 3.4 pints.
Don